New clues emerge on origin of Kepler's famous supernova

The remnant of Kepler's supernova, the famous explosion that was discovered by Johannes Kepler in 1604.
X-ray: NASA/CXC/NCSU/M.Burkey et al; Optical: DSS
More than 400 years after skywatchers -- including astronomer Johannes Kepler -- witnessed the appearance of a spectacular new star in the night sky, astronomers have uncovered important new details about the origins of this famous supernova.

The supernova remnant contains iron-rich material surrounded by an expanding shock wave that scarfs up interstellar gas and dust in its path. The ensuing shroud of gas and dust is estimated to be 14 light-years wide and is expanding at 4 million miles per hour.

A new study published online and in the February 10 issue of The Astrophysical Journal found that the explosion was both more powerful than astronomers believed and may also have taken place farther out in space than once thought. The supernova was originally viewed by naked eye as this was still the pre-telescope era. Estimates vary from 10,000 light-years to as much as 15,000 and 21,000 light-years. That original sight must have been something to see as it was generated by a thermonuclear blast which heated up gas temperatures to millions of degrees.

After poring over data supplied by NASA's Chandra X-ray Observatory, astronomers now believe that the supernova, first observed on Earth in 1604, was the result of a cosmic collision between supernova debris and material that the giant star expelled before the explosion. Another possibility about the supernova's origin is that the structure consists of just debris from the explosion.